This invention pertains to valves, notably cartridge-type pneumatic/hydraulic valves. It is particularly directed to an improved such valve useful for dental equipment.
Cartridge valves are commonly used in connection with dental equipment, as well as for other applications. FIGS. 1 through 4 illustrate typical such valves and the manner in which they are conventionally mounted in association with equipment. A common inconvenience experienced with available cartridge valves is the requirement for a tool of some kind to release the core assembly (cartridge) of the valve for servicing. Other types of toggle valves, which may perform functions similar to those of cartridge valves, are typically mounted in panels by means of jam nuts. While such other toggle valves are in common use, they are less desirable for many applications than are cartridge valves. Moreover, replacement of such valves requires the disconnection of fluid supply lines. It is believed that the cartridge valves currently available, which might otherwise be useful in dental equipment, are not appropriately structured for panel mounting with jam nuts; they are thus not directly interchangeable with the toggle valves already in place in the field.
According to this invention, a cartridge valve is constructed such that its core assembly is removable from the valve body without the use of a tool. Ideally, the core assembly is removable by simply pressing it axially inward with respect to the valve body, and rotating the core assembly radially to a release position. Preferred embodiments are constructed to mount to a panel by means of a jam nut threaded upon a terminal segment of the valve body near the actuation mechanism. Actuation may be by any of the mechanisms used in currently available valves; specifically including toggles, rollers and push buttons.
Generally, the invention comprises an improvement to cartridge valves of the type comprising a core assembly mounted within a valve body. The improvement comprises providing structure associated with the core assembly and the body, respectively, whereby the core may be selectively installed in and removed from the body by sequential axial and radial movements of the core with respect to the body. The valve body preferably further includes an extension constructed and arranged for insertion through an aperture of a panel structure. Ideally, the extension is approximately circular in cross section, and carries external threads. It thus constitutes means for mounting the valve body to the panel structure by means of jam nuts positioned on opposite sides of the panel structure. The core assembly may, for example, include a first coupling element and the valve body may carry a second coupling element, the first and second coupling elements being structured and arranged to provide a bayonet locking attachment of the core assembly within the valve body.
The first coupling element is preferably carried by the distal end of the core assembly and typically comprises a locking groove opening to the distal end, while the second coupling element comprises a structural element configured to register with the locking groove. In preferred embodiments, the locking groove is shaped generally as a xe2x80x9cJxe2x80x9d with a long leg opening to the distal end of the core assembly (cartridge), a transverse connecting leg at the proximal end of the long leg and a shorter leg spaced from the long leg and extending towards the distal end of the cartridge. The core assembly is then mounted within the chamber by registering the distal end of the long leg with the structural element, pushing the core assembly until the structural element is positioned within the transverse leg, turning the core assembly until the structural element registers with the shorter leg and causing the core assembly to move outwardly with respect to the chamber, whereby to register the structural element with the shorter leg towards the distal end of the cartridge. The structural element carried within the chamber of the valve body may comprise an indexing ball carried within a recess in the wall of the chamber.
According to highly preferred embodiments, the distal end of the core assembly carries a plurality of circumferentially spaced, xe2x80x9cJxe2x80x9d-shaped locking grooves structured and arranged such that at least one such groove will engage the second coupling mechanism when the core is rotated to any of a plurality of selected rotated positions with respect to the chamber. Ideally, the distal end of the core assembly caries four, evenly spaced locking grooves, and the second coupling mechanism comprises two structural elements projecting inwardly from the wall of the chamber to register with alternate such grooves.
A cartridge valve of this invention will thus generally comprise a body element having a distal end, a proximal end, an internal chamber defined by a chamber wall opening through the proximal end, an inlet port in open communication with the chamber and an outlet port spaced from the inlet port and in open communication with the chamber. The body element preferably includes an extension at its proximal end configured to enable mounting of the valve to a panel by means of jam nuts. The valve will further comprise a cartridge element, shaped and dimensioned for installation within the chamber. The cartridge element will ordinarily have a distal end and a proximal end carrying an actuator mechanism, a first sealing means disposed between the chamber wall and the cartridge element between the inlet port and the outlet port, respectively, and second sealing means disposed between the chamber wall and the cartridge element in a position to isolate both the inlet and outlet ports from the distal end of the chamber.
A bayonet locking system may be provided to couple the body element to the cartridge element, the locking system being structured and arranged to require push-turn-release manipulations of the cartridge element with respect to the chamber to install the cartridge element within the chamber and push-turn-pull manipulations of the cartridge element with respect to the chamber to remove the cartridge element from the chamber. The bayonet locking system may be structured and arranged to couple the cartridge element to the body element when the cartridge element is oriented in any of a plurality of selected rotated positions with respect to the chamber.
The actuator is generally operable between an ON position, which provides a fluid flow path between the inlet port and the outlet port through the cartridge element and an OFF position, which blocks fluid flow through the cartridge element. Valves of this invention may be provided with a plurality of interchangeable cartridge elements. Individual such cartridge elements may be distinct in at least one of actuation mechanism or internal configuration such that replacing one such cartridge element with another modifies the specific operation of the valve.